In many cases, the passport department has stopped affixing the usual exit/re-entry stamp on passports. They only mention the visa number and the validity of the visa - all jotted down by hand. This could create problems with the airlines while returning from Sri Lanka (or elsewhere), as the counters check the visa at the time of check-in.
To avoid this problem, go the Ministry of Interior website: www.moi.gov.sa. And then:
— Incidentally you can also view other details like traffic violations, visit visa application, etc. on this site.